Investments (Net Investment Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Investment Income [Line Items]
Less: Investment expenses	$ 313	$ 299	$ 615	$ 575
Subtotal	4,947	5,259	10,408	10,294
Securities Investment
Net Investment Income [Line Items]
Subtotal	5,309	5,248	10,391	10,472
Subtotal	4,996	4,949	9,776	9,897
Debt Securities [Member]
Net Investment Income [Line Items]
Subtotal	3,672	3,758	7,213	7,411
Equity securities
Net Investment Income [Line Items]
Subtotal	35	37	66	67
Actively traded securities and FVO general account securities [Member]
Net Investment Income [Line Items]
Subtotal	2	44	39	81
Changes in estimated fair value included in net investment income	(38)	14	(40)	25
Mortgage loans
Net Investment Income [Line Items]
Subtotal	801	708	1,531	1,417
Policy loans
Net Investment Income [Line Items]
Subtotal	151	158	303	315
Real estate and real estate joint ventures
Net Investment Income [Line Items]
Subtotal	323	262	534	479
Other limited partnership interests
Net Investment Income [Line Items]
Subtotal	250	206	465	535
Cash, cash equivalents and short-term investments
Net Investment Income [Line Items]
Subtotal	37	41	72	88
Operating joint ventures
Net Investment Income [Line Items]
Subtotal	8	3	16	3
Other
Net Investment Income [Line Items]
Subtotal	30	31	152	76
Consolidated Securitization Entities And Fair Value Option Contractholder-Directed Unit-Linked [Member]
Net Investment Income [Line Items]
Subtotal	(49)	310	632	397
FVO contractholder-directed unit-linked investments
Net Investment Income [Line Items]
Subtotal	(55)	295	622	360
Changes in estimated fair value included in net investment income	(288)	138	261	81
Commercial Loan [Member] | Consolidated Securitization Entities
Net Investment Income [Line Items]
Subtotal	5	14	9	36
Securities | Consolidated Securitization Entities
Net Investment Income [Line Items]
Subtotal	$ 1	$ 1	$ 1	$ 1